Oscillating phase-advancer.



e. KAPP.

OSCILLATING PHASE ADVANCEH. APPLICATION FILED NOV. 22. I915.

1 236,7 1 6. Patented Aug. 14, 1917.

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WITNESSES: INVENTOR Glsberf Kapp.

" '7 -'AT-TORNEY G. KAPP.

OSCILLATING PHASE ADVANCER.

APPLICATION FILED uovxzz. ms.

' Patented Aug. 14, 1917.

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INVENTOR Gisberf Kapp.

Zmimn UNITED STATES PATENT OFFICE.

GISBEBT KAIP, OF BIRMINGHAM, ENGLAND, ASSIGNOB TO THE WESTINGHOUSE ELEC-TRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

OSCILLATING PHASE-ADVANGEB:

Patented Aug. 14, 1917.

Original application filed March 4, 1912, Serial No. 681,458. Dividedand this application filed November 22, 1915. Serial No. 62,763.

'1 0 all whom it may concern:

Be it known that I, GISBERT KAPP,-a subject of the King of GreatBritain, and a resident of Birmingham, England, have invented a new anduseful Improvement in Oscillating Phase-Advancers, of which thefollowing is a specification.

My invention relates to apparatus for power-factor control, and it hasfor its object to provide a dynamo-electric machine that shall performthe function specified in an efficient and effective manner, thisapplication being a division of my application, Serial N 0. 681,458,filed Mar. 4, 1912.

In the accompanying drawing, Figure 1 is a diagrammatic View of adynamo-electric machine embodying one form of my invention; Fig. 2 is adiagrammatic view of a modification of the machine shown in Fig. 1; andFigs. 3 and 4c are top and side views, respectively, partially insection and partially in elevation, illustrating an actual embodimentofthe machine shown in Fig. 2 and adapted for power-factor control in aplurality of phases or in a plurality of independent circuits.

It is well known that the presence of inductive apparatus inalternating-current systems causes the current wave produced by avoltage wave to lag behind said voltage wave, thus lowering thepower-factor and producing ineiiicient transmission, poor regulation andother serious consequences.

By my invention, I employ a dynamoelectric machine wherein either thestator or the rotor winding is inserted in the alternating-currentcircuit in which it is desired to adjust the power-factor, and theremaining winding is excited from a source of direct current. The rotorof said machine is therefore oscillated in synchronism with thefrequency of the alternating current absorbing energy from the latterpor tion of each current wave, storing said energy in the form ofmomentum, and recuperating said energy ust before and upon the firstportion of the succeeding current wave, all in the general mannerdescribed in an article by M. Le Blane appearing on page 171 et seq. ofLEclaimge Electrique for Aug. 5, 1899. The phase of the resultantcurrent wave may be made to approximate that of the attendant voltagewave as closely as desired by proper design of the simplicity, shown asa ring winding, but it will be readily understood that a drum windingmay be employed. S is the iron core of the stator, carrying analternatingcurrent Winding W, Whose terminals are K K. M is a bar magnetpivoted at O and provided with a direct-current winding G which lattermay be put in series with the direct-current winding G, on the stator.The pole pieces of the magnet M are so shaped as to sweep as closely asis mechanically possible in front of the stator winding. By thisconstruction, with a given field excitation, a magnetic field of maximumstrength may be obtained. The terminals of the direct-current windingare marked k. k. I). D. are damping windings. The object of the serieswinding G is to secure to the magnet a zero position and to prevent itfrom vibrating through a greater angle than 90 degrees from the zeroposition. The latter is also the object of the damping winding. So longas no alternating current is sent through the stator, the vibrator willremain at rest in such position that its magnetic axis coincides withthe magnetic axis produced in the stator by its direct-current winding:this is what I have herein termed the zero position. If an alternatingcurrent of the low frequency of the slip is passed through the stator,the bar magnet M is acted upon by mechanical forces that alternate indirection with the alternations of the current and is thus set intovibration of the same frequency. Owing to the interaction between theseelectro-dynamic forces and the mass inertia of the vibrator, the zeroposition is passed at the instants when the current passes through zero,while the reversal of motion takes place at the instants when thecurrent has crest values. Since, on passing zero position, the vibratorhas maximum speed, the

E. M. F. induced in the stator winding is at these instants also atmaximum. It follows that the injected E. M. F. has crest value at theinstant when current passes through zero; and it has zero value at theinstant of reversal of movement when the current has crest value. Thus,the condition of quadrature between the current causing the "ibrationand the E. M. F. produced by this vibration is brought about. That theE. M. F. must be a leading E. M. F. will be obvious from the followingconsideration: After passing zero position in either sense, the currentopposes the motion and thus brings the magnet to rest at the end of itsswing. The energy stored kinetically in the vibrator is, during thisperiod, transferred electro-dynamically to the alternating-currentcircuit. The circuit receives energy during the time that the currentgrows. On reversal, when the vibrator approaches its zero position, itmust be accelerated by the dynamic force of the current. The vibratortakes energy from the circuit during the time that the current decreasesfrom its crest value to zero. Thus, the circuit receives energy whilethe current is growing and must yield up energy while the current iswaning, with the result that both the growth and decline of the currentare accelerated, which means that the phase of the current is advancedin relation to the E. M. F. of the slip which originally caused it toflow.

eferring now to Fig. 2, the effect of the improved arrangement islikewise due to "the relative motion between an alternating.-

current and a direct-current magnet, and, therefore, the explanation ofthis effect, as above given in connection with Fig. 1, isalsoirpplicable. When the alternating-current magnet is made theoscillating member of the system, it is of cylindrical shape andprovided with a drum winding and commutator similar to that used in adirect-current dynamo.

In the arrangement shown in Fig. 1, the angular deflection of theswinging system is limited to less than 90 degrees at each side of themid position. By the arrangement shown in Fig. 2, this limitation isremoved, and the magnitude of the injected E. M. F. is increased.

The essential parts of this arrangement of the vibrator are shown inFig. 2. The stator is constructed in the manner of the field-magnetsystem of a direct-current dynamo and is energized by the coils G. G. towhlch current from any convenient source is supplied through theterminals la la.-

The vibrator V is constructed after the manner of an ordinary directcurrent armature,

and the alternating current is supplied to it by brushes B, B bearing onits commutator. The vibrator V is of such size as to sweep as close asis mechanically possible in front of the pole pieces of the stator, asin the device of Fig. 1. Owing to the use of a com mutator, the angle ofvibration is not limited to something under 90 degrees, as in the firstdescribed arrangement, but may be any angle corresponding to theinteraction between mass inertia and the dynamic forces of thealternating current. Gommutating poles 0,, C, may be provided-althoughthe necessity of using them is less than in the case of a direct-currentdynamo, since, when the speed of commutation is at maximum the currentis at zerov and when the current is at maximum the speed of commutationis at zero.

Referrin to Figs. 3 and 4, a field frame S is provi ed and arranged tosupport any desired number of oscillating armatures V each of which isembraced by a pair of main poles excited by suitable direct-currentwindings G, G. Each of the vibrating or oscillating armatures V isprovided with a commutator C upon which bear brushes B for connection tothe alternating-current circuit in which the power factor is to be adjusted.

The fact that the commutated current is a maximum at standstill and aminimum at full speed so simplifies the problem of sparking at thebrushes that the short-circuit reactance of the coils undergoingcommutation may be disregarded. An air gap of minimum length may beemployed, therefore, thus permitting a very strong magnetic field and aresultant powerful operating torque, with the expenditure of but littleenergy for excitation. Furthermore, the presence of a strong field andsmall air gap minimizes the effect of unbalanced field and permits theuse of a relatively slender shaft, with still greater consequentpossibilities in the reduction of the reluctance of the magnetic pathand the resultant production of a strong flux with but little excitingcurrent.

I claim as my invention:

1. The combination with a dynamo-electric machine comprising an armatureprovided with a winding and a commutator connected thereto, brushesbearing upon said commutator, and a field magnet associated with saidarmature and provided with main and auxiliary field windings, of asource of alternating current, connections from said source through saidauxiliary field winding to said brushes, a source of direct current, andconnections from said direct-current source to said main field Winding.

2. The combination with a dynamo-electric machine comprising an armaturep-rovided with a winding and a commutator connected thereto, brushesbearing upon said commutator, and a field magnet associated with saidarmature and provided with a main field winding, of a source ofalternating current, connections from said source to said brushes, asource of direct current, connections from said direct-current source tosaid main field winding, whereby said armature is caused to oscillate,

and means for causing the efi'ective oscillating force in one directionto exceed that in the other direction.

3. The combination with a dynamo-electric machine comprising an armaturepro vided with a winding and a commutator connected thereto, brushesbearing upon said commutator, and a field magnet associated with saidarmature and provided with a main field winding, of a source ofalternating current, connections from said source to said brushes, asource of direct current, connections from said direct-current source tosaid main field winding, whereby said armature is caused to oscillate,and means for superposing on the unidirectional magnetic flux generatedby said main field winding an alternating magnetic flux of the frequencyof said alternating-current source, whereby the effective oscillatorytorque in one direction is caused to exceed that in the other direction.

4. The combination with a dynamo-elec tric machine provided with a woundarmature and with a field magnet and having the minimum air gaptherebetween that is mechanically possible, of a source of alternatingcurrent, connections from said source to the winding of said armature, asource of direct current, connections from said directcurrent source to.the winding of said field magnet, and means for causing the interactionof the field and armature magnetic fluxes to oscillate said armaturethrough a greater are than the polar pitch.

5. The combination with a dynamo-electric machine provided with a woundarmature and with a field magnet and having the minimum air gaptherebetween that is mechanically possible, of a source of alternatingcurrent, connections from said source to the winding of said armature, asource of direct current, connections from said directcurrent source tothe winding of said field magnet, said armature being mounted to befreely movable except for the forces exerted by the interaction of thefield and armature magnetic fluxes, and means for causing said forces tooscillate said armature through an angle greater than the polar pitch.

6. In a dynamo'electric machine provided with as short an air gap as ismechanically possible, the combination with a field magnet, of anarmature mounted adjacent thereto, each of said members being providedwith a winding, sources of direct and of alternating current,connections for energizing one of said windings from said direct-currentsource and the other of said windings from said alternating-currentsource, mounting means for said armature permitting it to oscillatefreely except for the forces exerted thereupon by the interaction of thefield and armature magnetic fluxes, and means for causing said forces tooscillate said armature through an angle greater than the polar pitch.

7. In a dynamo-electric machine provided with as short an air gap as ismechanically possible, the combination with two adjacent relativelymovable magnetizable members, each of which is provided with an excitingwinding, of sources of direct and of alternating current, connectionsfrom one of said windings to said alternating-current source and fromthe other of said windings to said direct-current source, whereby one ofsaid members is magnetized by an alternating flux and the other by aunidirectional flux and said members are caused to move relatively toeach other and an electromotive force is generated in saidalternating-current winding by cutting said unidirectional magneticflux, and means whereby a conductor of said alternating-current windingis caused to out said unidirectional field a plurality of times duringeach half cycle of alternating current.

8. An appliance adapted to be used for injecting a leading electromotiveforce into an alternating-current circuit, said app-li ance comprisingin combination, a fieldmagnet system of fixed polarity, a two pole,drum-Wound armature mounted with as small a clearance as is mechanicallypossible in said field-magnet system, a commutator, brushes adapted tobe connected to said circuit to lead current therefrom to said armatureto actuate the same, and means for supporting said armature in suchmanner as to leave it free to rotate alternately clockwise andcounter-clockwise, said armature being free from connection with anyother part or with any external force or controlling influence otherthan its electrical contact with the aforesaid brushes so that thevibratory movement of said armature will be produced solely by thepassage therethrough of the alternating current itself.

In testimony whereof, I have hereunto subscribed my name this 20 day ofOctober,

GISBERT KAPP.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of l'atents, Washington, D. 0.

